Control mechanism



E. G. GARTIN CONTROL MECHANISM.

APPLICATION FILED JAN. 3. 1920.

Patented Dec. 21, 1920.

I any.

nzer G. Am

El Q9 UNITED STATES. PATENT. OFFICE.

ELM ER G. GARTIN, 0F CLAREMONT, NEW HAMPSHIRE, ASSIGNOB 'IO SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS.

CON TBOL MECHANISM.

Specification of Letters Patent.

Patented Dec. 21, 1920.

Application filed January 3, 1920. Serial No. 349,346.

To all whom it may concern:

Be it known that I, ELMER G. GARTIN, a citizen of the United States, residing at Claremont, in the count of Sullivan and State of New Hampshire, have invented certain new and useful Improvements in Control Mechanism, of which the following is a full, clear, and exact specification.

My invention relates to control mechanism.

It has for its object to provide an im- 3 proved feed controlling mechanism and one especially adapted to use on percussive tools of the fluid pressure fed type, such, for example, as stopers, and, more particularly to provide an improved braking mechanism for controlling the rapidity of feed of such devices. A further object of my invention is to provide a controlling mechanism which is qulck in operation, and in which a relatively small movement of the control mechanism causes a relatively great movement of the brake.

In the drawings, for purposes of illustration, I have shown one form which my invention may assume in practice.

In these drawings,-

Figure 1 is a s1de elevation of a pneumatically fed tool, the rear end of the feed cylinder and a portion of the piston rod being broken away.

Fig. 2 is a section of my improved feed controlling mechanism onthe line 2 2 of Fig. 3. ig. 3 is a transverse section through the controlling mechanism housing on line 3-3 of Fig. 2 with the control mechanism shown in elevation, and parts broken away to show structural details.

Fig. 4 is a transverse section showing a structural detail on the line %14 of Fig. 3.

In this illustrative disclosure of my invention, a base 1 is provided having adjustably secured thereto the feed cylinder 2 of a usual form of pneumatic drill 3, the feed of the drill 3 being effected by movement of the piston 1 and of the piston rod 5 of the feed cylinder, and the feed being controlled by supply and exhaust of pressure fluid in a well-known manner through ports 6 and 7 extending through the piston rod, and by the coiiperation of improved feed controllin mechanism hereinafter described.

rranged on the forward end of the feed cylinder I have provided an enlarged houscollar ofbrake material 12 mounted in an elastic split metal housing 13. For the purpose of applying and permitting release of this brake, there is provided a resilient spirally coiled spring member 14 having one end thereof held in fixed relation to the housing by a projecting lug 15 and hav- 1ng the other end thereof provided with a radially bent end engaged in a socket 16 formed in a worm wheel 17. The wormwheel 17 is mounted in such manner as to be freely rotatable in the housing 10 but is fixed against movement in the direction of motion of the piston. In order to provide a freely rotatable bearing for the worm wheel, the lateral portions of its periphery are smooth, but the central portion of its periphery is provided with suitable teeth 18 to cooperate with the teeth formed upon a worm 19. The worm 19 is suitably journaled in a transverse enlargement 21 of the housing 10, being formed upon'a shaft 22, and a spring 23 is interposed between the worm and the inner end of the housing 21 and surrounds the shaft. A hand wheel 24 is secured to the opposite end of the shaft 22. The structure so far described is of well-known commercial construction and no claim is made to it per 86.

Owing to the worm and wheel construction and the length of the spiral spring tensioning member, a considerable rotation of the hand Wheel 24 secured to the shaft 22 would be necessary to effect. tightening or loosening of the brake material 12. As I have found that in some cases it is desirable to permit a rapid adjustment of the tension of the brake upon the piston rod, I have devised the improvement consisting of clutching, as at 27 to the hand wheel 24 a collar 25 which has a threaded engagement with an-opening 26 formed in the end of the transverse housing 21. The worm teeth 19 are formed with a left hand thread so that by imparting a right hand turn to the shaft 22, the worm wheel in Fig. 3 will be caused to turn in the direction of the arrow, or clockwise. By providing a right hand thread connection between the parts 25 andlgb 26, it will be obvious that a right hand turn of shaft 22 will cause the worm 19 to 'be bodily moved to the right in Fig. 3 which will likewise' cause an additional movement of the worm wheel in the direction of the arrow in this figure. It will thus be seen that I have provided a device for increasing the, ra idity of motion of the worm wheel 17 and accordingly that I have provided a more rapid method of adjustment for the tension adjusting member 14.

While I have shown and described only a single thread construction, it will be obvious that double or even triple threads might be readily used with a resultant greater rapidity of adjustment than in the device which I have illustrated. The great advantage of my construction is that by the arrangement of the parts as illustrated, twice the speed of adjustment can be obtained without change in the pitch of either of the screws, assuming that the pitch of the screw and of the worm is the same, and accordingly the tendency to slip will be no greater than were my second screw connection omitted. It will also be evident that, if desired, the pitch and the threads of either of the screws embodied in my device may be varied to obtain any combination of motion desired.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the inventlon may be modified and. embodied in other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is: a

1. In a control mechanism, a longitudinally movable member,a rotatable member, a braking member cooperating with the former and having one end thereof fixed and the other end thereof secured to said rotatable member and adapted to be tight ened or slackened by rotation of said member, gearing adapted to rotate said member, and means for causing simultaneous rotative and rectilinear movement of one element of said aring.

2. n a control mechanism, a longitudinally movable member, a worm wheel relative to which said longitudinally movable member is movable, a braking element surrounding said member and having one end thereof fixed and the other end thereof secured to said worm wheel, a worm to rotate said wheel, a fixed nut, and a screw cooperating with said worm and said fixed nut her, a braking element cooperating withsaid longitudinally movable member and having one end thereof fixed and the other end thereof secured to said rptatable member and adapted to be tightened or slackened by rotation thereof, and a toothed driving member engaging said toothed rotatable member, of means to cause rotative movement of the teeth of said toothed driving member and a simultaneous movement of said teeth in a direction tangential to the toothed rotatable member.

4:. The combination with a gear, of two telescopically arranged members and a holical member coiled about one of said telescopically arranged members and having one portion fixed as to circumferential movement and another portion thereof secured to said gear, said gear being coaxially disposed with respect to said last mentioned telescopically arranged member, together with a Worm to rotate said gear, and a screw coaxially arranged with respect to said worm and adapted to move it longitudinally and rotate it simultaneously.

5. The combination with a gear, of two telescopically arranged members and a helical member 'coiled' about one of said telescopically arranged members and having one portion fixed as to circumferential movement and another portion thereof secured to said gear, said gear being coaxially disposed with respect to said last mentioned telescopically arranged member, together with a worm to rotate said gear, and a screw coaxially arranged with respect to said worm and adapted to move it longitudinally and rotate it simultaneously, the rotative effect of said worm and said screw on said gear being additive.

6. The combination with two telescopically arranged members, a worm wheel rotatively arranged around one of said members, a helical member coiled about the said member having one portion thereof fixed and another portion thereof secured to said worm wheel, a worm cooperating with said worm wheel, and a shaftupon which said worm is mounted, of a fixed nut, a screw englaging said fixed nut and secured to said s aft, and means for rotating said shaft to impart to said worm wheel the cumulative effect of said worm and of saidscrew.

In testimony whereof I aflix my signature.

ELMER G. GARTIN. 

